OSC: UNKNOWN QUANTITY OR TANGIBLE GAIN?

AUSTRALIAN INSTITUTE OF QUANTITY SURVEYORS (AIQS) CEO GRANT WARNER ASSESSES THE OPPORTUNITIES AND CHALLENGES OF PREFAB OR OFF-SITE CONSTRUCTION (OSC) IN THE AUSTRALIAN MARKET.

There are opportunities for increased utilisation of Off-Site-Construction (OSC) across the residential and commercial construction sectors, which have adopted OSC at different rates; while significant improvements have been made in the use of Off-site / Modular / Containerised construction products in residential construction, adoption by the commercial construction sector has been more limited.

Increased utilisation of OSC will occur once architects/designers understand the structural and design limitations associated with OSC. This understanding, together with careful cost planning and good control of the design, could make OSC for both the high-rise residential and the commercial sectors more viable. However, many of these cost savings are lost because of Building Code of Australia requirements, which stipulate that buildings of three floors or more, must have concrete or masonry fire escapes.

That said, the cost-benefit of utilising OSC does not always support the use of Off-site / Modular / Containerised construction. While there are benefits associated with installation time, cost, regional location, quality of workmanship, and reduction in waste and unnecessary labour, restrictions associated with transport (size, weight, shipping delays, cost), and design limitations often counter the benefits.

To offset this, better and more innovative designs, which suit modular type construction, utilising Building Information Modelling (BIM), and innovative building products which may provide greater flexibility could lead to increased use of OSC. With the right sort of advancements, opportunities may exist in the industrial and healthcare sectors, for utilisation of OSC techniques.

Significant improvements in the utilisation of OSC will ultimately be driven by economic factors. Improved communication and collaboration between designers, builders, cost planners, manufacturers of off-site products, and suppliers of innovative building products, could lead to a significant increase in the level of OSC across the construction sector.■